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gc sections and .eh_frame

Jonathan Larmour jifl@eCosCentric.com
Thu Jun 9 14:33:00 GMT 2005 
Eric Botcazou wrote:
>>That's quite a sledgehammer approach! The overhead of garbage collectable
>>stuff in .rodata is substantially more than .gcc_except_table. For my own
>>use, right now, I've just reverted the patch.
> 
> 
> Since -function-sections --gc-sections doesn't work in presence of DWARF-2 EH, 
> you could simply not pass -function-sections to the compiler.

Ah, the issue being on embedded targets (as powerpc-eabi is implicitly), 
people are normally selective about what they allow to be compiled without 
-fno-exceptions. In the case of eCos, the OS is fully linked to the 
application, and almost none of the OS wants to use C++ exceptions. This 
translates to large savings with gc sections.

I expect anyone else using eCos or their own embedded OS would be 
similarly selective.

> I'm not sure the .gcc_except_table section has already been created by the 
> time bfd_elf_gc_sections is invoked.  I'm looking into it.

Great, thanks. I guess looping over the input BFDs would be better.

Jifl
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